Cream the butter and both sugars in the bowl of a stand mixer fitted with a paddle attachment (or a large mixing bowl if using a hand-held mixer) on medium speed until light in color, 3 to 5 minutes. Add the eggs and vanilla, and beat until fluffy, 1 to 2 minutes. Mix in the oats until just combined.

Add the dry ingredients in thirds until just combined, for no more than 2 minutes. Sprinkle in the toasted coconut and raisins and stir until just combined.

Scoop the dough onto the prepared cookie sheets with a large ice cream scoop, leaving 1 inch between each cookie to ensure even baking. Lightly tap down each cookie with the palm of your hand and sprinkle with just a pinch of turbinado sugar. Bake for 8 to10 minutes in the middle of the oven, rotating the sheet half way through the baking time for even doneness.

For the filling: Cream the butter on medium speed until light and fluffy, 2 to 3 minutes. Add 1 cup of the confectioners' sugar, milk and vanilla, and mix on low speed until smooth and creamy, 1 to 2 minutes. Add the second cup of sugar while mixing on low speed until the filling reaches the desired light and fluffy consistency, 2 to 3 minutes.

To sandwich the cookies: Put a dollop of filling (about 1 tablespoon) on the bottom of one cookie and place the other cookie right side up on top. Repeat with the remaining cookies.

This recipe was provided by a chef, restaurant or culinary professional and may have been scaled down from a bulk recipe. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.